Automatic starter for electric motors.



LVBRADLEY. v AUTOMATRC STARTER FOR ELECTRIC MOTORS.

APPLICATION FILED AUG. 10, 1911.

Patented Nov. 23, 1925 2 SHEETS-SHEET 1.

l'vnvnte 2 a M I &4.

eattorm 85 5 L. BBAIJLEY.

AUTOMATIC STARTER FOR ELECTRIC MOTORS.

APPLICATION FILED AUG-l0; 1911.

1,1 61,021. Patented Nov. 23, 1915.

2 SHEETS-SHEET 2- Inventor STATES PATENT omen.

azure BRADLEY, or m1LwAuKnn;-- w1scousnt.

To all whom it may concern I Be it known that I, LYNDE BRADLEY, a

- Improvements in citizen oftlie United States, residing at Milwaukee, county of Milwaukee, and State of Wisconsin, have invented new and useful Automatic Starters for Electric Motors, of which the following is a specification.

My invention relates to improvements in current controlling devices, with especial I reference to that class of controlling devices such electrical circuits may be automatically "reduced and finally cut out entirely. The

advantages thus secured reside not only in the fact that the operator is relieved of the necessity of operating a controller lever, but also in-the fact that the reduction in the resistance is made uniformly gradual, and the variations are of less magnitude than they are apt to be where a controller lever is-em- 'ployed.

My invention is also peculiarly adapted for use in starting motors, since it provides means for varying the motor startinginterval in proportion to the load.

In the drawings :-Figure 1 is a front elevation of a controller embodying my invention, showing the solenoid and relay in central vertical section, and the resistance coli umn partially in vertical section.

Figs. 2, 3 and tare diagrams illustrating the circuits as they are successively established during a motor starting operation, Fig. 2

' illustrating the initial-circuits, Fig. 3 the erence characters intermediate circuits, and Fig. 4 the final or normal working circuits.

Like parts are. identified by the same refthroughout the several views.

The circuit of the motor 1 is closed by an ordinary switch 2. Initially, this circuit includes a variable resistance column 3 which may be assumed to be similar to those de- ';"scribed in my formed patents, above re-' ferred to. In my improved apparatus, how- .ever, I employ a'solenoid 4 arranged in. a

Specification of Letters Patdnt.

AUTOMATIC STARTER non ELpeTmo morons.

shunt circuit and operating through a lever 5 to apply pressure to the resistance column 3 during the motor starting period. During the motor starting period, the shunt circuit is controlled by a relay switch 6, the-latter being included in circuit with the resistance column and also in the circuit of the motor. The relay operates to prolong the interval of pressure increase upon the column 3, by intermittingly and momentarily inter-posing a high'resistance 7 in the shunt circuit, sufiicient to'inte'rrupt the efi'ective How of current to the solenoid winding, and for a period of insufficient duration to allow the solenoid core to return to its normal position and entirely relieve the pressure upon the column 3. The resistance 7 operates in substantially the same way as a circuit breaker, s1nce it cuts out the electro-magnet by substantially interrupting the current in the shunt circuit. By the alternate operation of the solenoid and relay switch, I am enabled to apply a pressure to the resistance column 3 which increases step by step and but slightly at each step, whereby a substantially gradual or steady increase of pressure is secured. During the final upward movement of the solenoid core, the pressure upon the column 3-reaches a maximum, and the resistance of said column to the passage of current reaches the minimum, whereupon the solenoid actuates a switch member 8 into circuit closing relation with a contact member 9 to cut out both the resistance column 3 and the relay switch 6, the motor being then substantially at full speed.

The resistance column 3 is, as above stated, similar to those shown and described in my former patents. .But for my present purposes it is preferably mounted upon the lever 5 and lifted bodily thereby. At its upper end, it is provided with a head block a, having a stem 7; adapted to bear against a; resi1ient stop 0. A cap d covers the top of the column and is provided with depending annular flanges e, e, the outer flange e embracing the upper end of the column incl0sing casing, and the inner flange e fitting an annular channel in the cap block, thus preventing a free passage of air to the interior of the casing without sealing the casing against the escape of air or gas when the column is heated.

The relay is wound for apredetermined amperage and is included in the circuit of the column 3. When the resistance of the Patented Nov; 23, 1915. Application filed August 10, 1911. Serial No. 643,329: I I

the relay will continue column is reduced by pressure, as above explained, the relay armature will be actuated as soon as the volume of current is suliicient, and this separates contact member 9 from the stationary contact member h. Initially, the circuit of the motor, (Fig. 2) is from the switch through line 10, column 3, line 11, the winding of the relay, line 12 to the motor, and line 13 to the switch, the shunt circuit being through line 14 to the solenoid 4, line 15, contacts 9 and h, and line 16. But when the relay armature lifts,-separating contacts g; and It, (Fig. 3) the electrical connection of line 15 is to the high resistance 7 and by line 17 to contact k.

The solenoid core 71 moves downwardly by gravity when the current to the solenoid is checked by the resistance 7, and this causes an instant diminution of pressure upon column 3, with consequent increase in resistance and a reduction in the volume of the current through relay 6, sutiicient to permit its armature to descend until 9 and it are again in contact, thus restoring the shunt circuit of Fig. 2 and causing another upward movement of the solenoid armature. These alternative oscillations of the relay and solenoid armatures continue until the solenoid core 2' actuates switch member 8 into engagemeht with contact 9, whereupon the circuit of the motor will be (Fig. 4) from switch 2 through line 10 through lines 14 and 19, contacts 9, switch member 8 and lines 20 and 12 the motor, and the line 13 to the switch. The shunt circuit through the solenoid 4 then is .as shown in Fig. 4;, while switch 2 remains closed.

l/Vhile I have shown and described the resistance column 3 as similar to those shown in the above mentioned former patents, it will be understood that any suitable variable protective'resistance may be employed, and I therefore do not limit my claims to a resistance column of specific type. Neither is the specific structure and arrangement of the various parts regarded as essential, although I prefer to employ a lever 5 to lift the column against a cushioned stop 0 and to allow the units to separate by gravity when the pressure is relieved. A resilient stop is provided in order to avoid shocks, and for the same reason the solenoid core 2' is connected with lever 5 by a yielding link comprising a rod [6, which extends through a slot in the lever, and carries a coiled spring Z which supports a movable lever engaging block m.

27 are fuses of ordinary construction.

With this invention the duration of the interval of progressive resistance column compression is proportioned to the time re quired for developing full speed in the motor, that is to say, it depends in duration upon the load. This is due to the fact that to cut out the solenoid (interpose the high resistance), until. the speed of the motor reaches a point where the counter electro-motive force will develop to such an extent as to hold the amperage below that required for relay opera tion. As the speed of the motor increases, the solenoid core successively moves to higher and higher points until the maximum pressure is exerted upon the resistance column, and until said column, with the relay, are cut out as above explained. The armature core a is preferably arranged to serve as a plunger in the solenoid cavity. Packing rings 24- may be employed to pre vent the free entry and escape of air, to and from this cavity, thus checking the momentum of the core in either direction to pre vent injurious pounding.

Means for adjusting the relay to operate at different amperages, are preferably provided. This is simply accomplished by providing an adjustable support for the contact member 11,, which member serves as a stop limiting the downward movement of the armature. To this end the stop 71 is supported by a screw 25, and a lock nut 26 employed to secure it in any desired posit-ion of vertical adjustment. I

I claim 1. An electric current controller, comprising the combination with a main electrical circuit, of a variable resistance member in said circuit, electro magnetic mechanism operatively connected therewith to vary the resistance, and a relay switch in said main cir- 100 cuit, operatively arranged to interrupt the effective flow of current to the electro-magnetic mechanism sutliciently to temporarily render the electro-magnet inoperative.

2. An electric current I ing the combination with a main electrical, circuit, of a. relay switch and a variable resistance column included in said circuit, electromagnetic mechanism included in a shunt from said main circuit/and adapted 110 to vary the pressure upon said column, and means for utilizing the relay switch to interrupt the flow of effective current to said electro-magnetic mechanism whenever the flow of current through the relay exceeds a predetermined limit, whereby a partial reduction of pressure upon said column is permitted during each operation of the relay switch. 3. An electric current controller, compris- 0 ing the combination with a main electrical circuit, of a relay switch and a variable resistance member included in said circuit, electro-magnetic mechanism included in a shunt from said main circuit, and adapted to varv the resistance. of said member in the main circuit, and means-for utilizing the relay switch to interrupt the effective flow of current in said shunt circuit whenever the flow of current through the relay controller compris- 105' 4. An electric current and means for, pr

exceeds ahpr edetermined limit, together withv me ns controlled by the netic mechanism during a electro-magfinal operation thereof, tor cutting out the relay switch andresistance member.

.from the main circuit.

controller, compris-v ing the combination with ajmain, electrical cluded'in said circuit; a shunt "iarytosaid rum nmechanism in said variable resistance column incircuit auxilc rcuit, electro-magnetic shunt circuit, adapted to compress theT'variableresistance .column'.

" ve y n 'wa the movableparts ohsaid mechan sm trom the electro-ma Aulelectric current V combination -with a mam electrical ing the o g eet 'c Pu l.

the interyal of v temporarily rel1eving I I controller, compriscircuit, of a variable resistance member in.-

eluded ii1-said-circuit, a D

to said main c rcuit, electro-magnetic shunt circuit auxilmechanism in said/shunt circuit, and con- .trrupting iirom said trolling the variable resistance mem means. for 'pr'olon'g tro-mag'netic control by" the .eifective currenti in said shunt. circuit, and temporarily relieving the I resistance member 7 An electric-current controller, comprisber, and g 1 1. I nterval of elec- "ntermittingly mof such control.

ing thef'eombination with a main electrical includes,- a fvariable resistance column'in which theresistance is reduced by compression, of af'srfienoid main circuit,

in shunt circuit a switch adapted to be operatedbyathesolenoid, when energized,

to cut out. said "resistance column, switch, energized by circuit to releasethe when the main circuit netic pull a relay the current in the main solenoid core from magcurrent ex ceeds a predetermined volume, and means,

operated by said solenoid, for-progressively compressing the resistance column preparatory to cutting it out of said circuit.

7. An electric current controller, comprisingthe combination with a main electrical circuit having a variable resistance column included therein, and in which the resistance is reduced by compression, porting said column,

tween which and the lever, be compressed,

a solenoid of a lever supa yielding stop be the column mayhaving a movable member connectedwith the lever, shunt connection for intermittingl y energizing said solenoid from the main circuit, a switch for cuttin out said trolle movement of the means for delaying the movement during the compressing opmovable m ember eration.

resistance column, conby said solenoid during the final member, and of said movable 8. An electric circuit controller, cofmprising the combination with a main;- circuit, of. a current regulatingemember, ele'ct'ro-mag- 'netic mechanism ber and adapted t for controlling said menu- 0 both increase=and de-;

. tion, a switch adapted to mechanism to cut out said member from said supply to the main circuit, and a relay switch in said circuit adapted to interrupt and reestablish the efiective current delivere to the electromagnetic mechanism in accordance with the number of amperes delivered. I

9. An electric current controller, comprising the combination with a main circuit, of a variable resistance column included in said circuit, electro-magnetic mechanism in shunt with said circuit and operatively connecte to vary the resistance of said column, a relay switch in circuit with'the resistance column, and a high resistance member adapted to prevent effective current delivery to the electro magnetic mechanism, j said relay switch being adapted to operate under a predetermined current volume to temporarily interpose the high resistance member in said shunt circuit when the current in the main circuit exceeds a predetermined volume.

10 ,An electric current controller, comprising the combination with a main circuit eluded therein, of a solenoid provided with said solenoid when the current in the mam having 'a variable resistance member inamovable core operatively connected to vary the resistance of said member, a current controlled switch for substantially deenergizing circuit exceeds a predetermined volume, and

aswitch member in the path of the solenoid core adapted to be actuated during the final movement thereof in one direction to cut out said currentcontrolled switch and resistance member from the main circuit.

11. The combination with a motor circuit,

of a resistance column in said circuit, electromagnetic means for progressively compressing the same, mittingly interrupting the efiective current electro-magnetic mechanism during the motor starting intervalj 12. The combination with a motor circuit, of an electro-magnetically compressed resistance member in said circuit, and electrically operated means for alternately increasing and decreasing the pressure upon said member during themotor starting interval to regulate the current to the motor and also lengthen said interval,

13. Thejcombination with a main circuit, and a variable resistance column in said circuit, of electrical means for varying the resistance of'said column and electrical means also included in the main circuit for successively interrupting the efi'ective supply of current to the resistance varying means to prolong the period of variation.

, l5}; The combination with an electrical circuit', of a variable resistance member, electromagneticcontrolling mechanism therefor, a member for automatically relieving said controllingmechanism of efiective magnetic ins,

and a relay, switch for inter-- fiuence in successive brief intervals while permitting progressive variation of the resistance during the intermediate periods, and a device operated by the controlling mechanism during its final resistance varying movement, for cutting out the variable re sistance and relieving members from said circuit.

15. An electric current controller, comprising the combination with a main electrical circuit, having a variable resistance column included therein, electro-magnetic means for varying the pressure upon said column to both increase and decrease such pressure at intermediate stages of set of gradually increasing pressure changes, and a switch for cutting out said column from the, electri -al circuit, controlled as to operation, by the electro-magnetic means during the final pressure applying operation.

16. An electric current controller, comprising the combination with a main electrical circuit, having a variable resistance column included therein, electro-magnetic means for varying said resistance by successively applying increased and reduced pressures to said column with accumulating in-.

creased pressure, and means, controlled by said electro-magnet, for cutting out the resistance column from said main circuit, when the pressure thereon exceeds a predetermined maximum. v

17. An electric current controller, comprising the combination of a variable resistance medium in which the resistance is varied by compression, electro-magnetic means for compressing said medium, means adapted to be controlled by the current voL ume passing through the resistance medium for checking the operation of the electromagnetic means at any and all times during the compressing operation, whereby the resistance of said medium is subjected to constant and continuous current volume control during the ompression period.

18. An electric current controller, coniprising the combination with a main electricalcircuit, of variable resistance member included in said circuitr electromagnetic means for operating said member to vary the resistance,.relay switch mechanism in said circuit for intermittingly interrupting the effective current to the electromagnetic means to delay 'the period of resistance variation, and means for adjusting said relay sWitch mechanism to operate under different conditions of current volume.

19. An electric current controller, comprising the combination vvith a, main electrical circuit having a variable resistance column included therein, and in Which the resistance is reduced by compression, of a lever supporting said column, a yielding stop bet veenwvhicli and the lever, the column may be compressed, a. solenoid having a movable member connected With the lever, shunt connections for energizing said sole; noid from the main circuit, a switch for cutting out said resistance column, controlled by said solenoid during the final movement of the movable member, and means for operating said movable member in two directions during the compressing period to increase and decrease the pressure, together with means for pneumatically cushioning the movable member of the solenoid.

20. An electric current controller for motor circuits, comprising the combination of a variable resistance medium, in which the resistance is varied by compression, an electro-magnetic device having a movable member for compressing said medium, said device being adapted to respond constantly during the compressing period to va iations of current volume in the motor circuit,

means for cutting out said medium from an electrical circuit at a predetermined stage of compression, and means for pneumatically cushioning the movable member of the elec tro-magnetic device.

21. The combination with a motor armature circuit, of a compressible resistance member in said circuit, a solenoid having a movable core provided with connections adapted to apply pressure to the resistance member, and a relay in the motor armature circuit adapted to regulate the movement of the SO lQHOld core in accordance with the cur-- rent volume in said armatur circuit.

In testimony whereof I athr; my signature in the presence of two "Witnesses.

LYNDE BRADLEY.

V'vitnesses Lnvnnnr'r C. WHEELER,

1. D. Benzene, 

